Why an earlier War of 1812 would not spare the United States

If the War of 1812 had begun in 1810 while the Royal Navy was still blockading France, what could Britain have sent to North America?

Probably a broadly similar force, while the United States would have entered the conflict less organized and less prepared than it was in 1812.

The Royal Navy could activate additional ships and send a force broadly comparable to the historical one despite the continuing French blockade. The United States had used the intervening years to improve its organization and naval readiness. Moving the war earlier changes both sides' starting positions rather than simply subtracting British strength.